1. Field of the Invention
The present invention relates generally to a home network system, and more particularly, to an apparatus for restoring network information for a home network system and a method thereof.
2. Description of the Related Art
Currently, a home network system have been commercialized for the pursuit of convenience for control, monitoring, etc., of home appliances indoors or outdoors.
In the home network system, it is essential to construct communication lines for exchanging signals among the home appliances and a network controller for controlling the home appliances.
The home network may be constructed using separate communication lines, but it is preferable to construct the home network using power lines for supplying a power in the home.
As the technology in this field has been greatly developed, the home network system will adopt a communication method using the power line in future.
Although a separate appliance may be adopted as a network controller, the system may be constructed in a manner that any home appliance, which has a display function and connects to the Internet, such as an Internet TV, a personal computer, an Internet refrigerator, etc., is determined as a network controller, i.e., a master, and other home appliances are determined as slaves.
For example, as shown in FIG. 1, in the case that a home network is constructed among a TV (e.g., a digital TV), a washing machine, a microwave oven, an air conditioner, etc., the TV may be determined as a master and the washing machine, the microwave oven, the air conditioner, etc., may be determined as slaves.
The master and the slaves are connected to power-line communication modems, respectively, and the power-line communication modems are connected to outlets corresponding to power-line nodes A, B, C and D, so that the home network system is constructed.
Now, a communication process performed between the master and the slaves in the home network system as constructed above will be explained.
First, in the case of a normal communication as shown in FIG. 2a, the master requests a predetermined command to the slaves to start the communication, and the slaves respond to the master to complete the communication.
Meanwhile, if an error occurs during the communication as shown in FIG. 2b after the master requested the command to the slaves, the slaves fail to respond to the master. In this case, the master waits for a response from the slave for a predetermined time, and if no response is received after the predetermined time, the master re-requests the command to the slaves. If the slave responds to the master at that time, the communication is completed.
In the home network system, the master, e.g., the TV, controls various functions of the slaves including an on/off control of the power supplied to the slaves by a home network control program. The master also controls the registration and management of new home appliances, gives IDs for data communication to the slaves, and displays a picture for controlling the registered appliances.
When the power is supplied normally, the master and the slaves perform their normal operations. However, if slaves are reset due to an instantaneous power failure or any abnormal operation of the slaves and thus the slaves lose the operation-related network information, the slaves fail to remember their operation states before they are reset, and thus cannot perform their corresponding operations.
Therefore, when the power is supplied after the power failure, a user must reset the operation-related network information through the master or the slaves.
As described above, the conventional home network system has the drawbacks in that if the network information related to the operation of the slaves is lost due to an instantaneous power failure or an abnormal operation of the slaves, the user must reset the network information, and this causes inconvenience to the user. Also, as the number of slaves increases, the time required for resetting the slaves also increases.